KR100441145B1 - Automatic roaming System and method for location based service - Google Patents

Abstract

The present invention relates to a location-based service system (LBS system), such as a CDMA-based wireless PABX system, a wireless office system (WOS), a CDMA Tiered Service (CTS), and the like in an existing CDMA cellular system and / or a CDMA PCS system. In this case, when the frequency assignment between the LBS system and the public system is different, LBS system subscriber terminals crossing between these systems will be able to switch the system automatically without user manual operation. An automatic roaming system and method for location-based services to enable the present invention. The LBS system subscriber station may be a public terminal or an LBS dedicated terminal. Here, only the case where the LBS system subscriber terminal is a public terminal is considered. The method proposed in the present invention is to build a separate internal cell (hereinafter referred to as "LBS macrocell") for the public system that is built inside the LBS system area (hereinafter referred to as "LBS local") under the control of the LBS macrocell It is characterized in that only the LBS subscriber station is switched to the LBS system or by transmitting an intermittent synchronization beacon periodically from the LBS local to control only the LBS subscriber terminal entering the LBS local for a certain period of time to switch to the LBS system, intermittent synchronization Unlike conventional beacons, the beacon device is characterized in that it is transmitted at a specific period in synchronization with the CDMA system time.

Description

Automatic roaming system and method for location based service

The present invention relates to a frequency assignment between a "CDMA cellular system and / or a CDMA PCS system" (hereinafter referred to as a public (public) system) and a Location Based Service System (hereinafter referred to as an LBS system); Automatic roaming system that allows location-based service system subscriber terminals (hereinafter referred to as " LBS subscriber terminals ") crossing between these systems to automatically switch the system when the FAs are different; It is about a method.

LBS systems such as a CDMA-based wireless PABX system (hereinafter, referred to as a "WPABX system"), a WOS (Wireless Office System), and a CDMA Tiered Service (CTS) support the same mobile terminal as a public system. That is, the LBS system subscriber (hereinafter referred to as "LBS subscriber") is usually used as a public terminal in the public system area using a conventional mobile terminal for mobile system (hereinafter referred to as "public terminal"), and then in the LBS system area. When entering inside (hereinafter referred to as "LBS local") is used as an LBS subscriber station. In addition to the services provided by the public system, the LBS system provides additional LBS local-specific services, and the service charges in the LBS local service are differentiated from those provided by the public system. For example, a local call within a WPABX system can be free or much cheaper than billing for a call in a public system. The WPABX system may use the same frequency allocation as the public system or may use a separate frequency allocation. In the present invention, only the LBS system using the separate frequency allocation is used.

Conventionally, hard handoff between frequencies has to be used for automatic system switching between a public system having a different frequency allocation and an LBS system by using an existing public terminal. In this case, the public terminal and the LBS subscriber station may be used. It was not possible to switch only LBS subscriber station to LBS system. For this reason, there is a problem in that it is difficult to differentiate in the service and billing policy for LBS subscriber stations in the past.

The present invention is to solve the above-described problems, the mobile terminal is a LBS macro by building a separate internal cell (hereinafter referred to as LBS macro cell ") for the public system that is built in the LBS system area (LBS local) It is an object of the present invention to provide an automatic roaming system and a method for controlling handoff to a LBS system among terminals existing in an LBS macrocell after being handed off to a cell.

In addition, the present invention is to automatically transmit the intermittent synchronous beacon (Sporadic Beacon) in the LBS local instead of building the LBS macrocell to control the LBS subscriber stations entering the LBS local for a certain period of time to switch to the LBS system Another object is to provide a roaming system and method thereof.

In order to achieve the above object, an automatic roaming system for a location-based service according to the present invention includes a location-based service system having a different frequency allocation, and an access overload class in a public system of a CDMA cellular and / or CDMA PCS system. A classification means for distinguishing between a public terminal for a public system and a location-based service subscriber terminal using an access overload class; It is characterized in that it comprises an automatic switching means for configuring the location-based service macrocell to automatically switch only the location-based service subscriber station of the idle state (Idle) entered into the location-based service system coverage to the location-based service system.

Here, the location-based service subscriber station is set to a value different from the public terminal, the value of the access overload class, the switching means is a different value from the public terminal, entering the location-based service macrocell Control to switch only the terminal having the value of the access overload class set to the location-based service system.

And, the location-based service macrocell preferably has a coverage equal to or less than the location-based service system coverage.

In addition, the automatic switching means uses the overhead message transmitted periodically, the location-based terminal having a value of the access overload class set to a value different from the public terminal, which enters the location-based service macrocell coverage Automatically switch to service system. In addition, the overhead message includes a Global Service Redirection Message (GSRM) for the location-based service subscriber station.

In order to achieve the above object, an automatic roaming system for a location-based service according to the present invention includes a location-based service system having a different frequency allocation, and an access overload class in a public system of a CDMA cellular and / or CDMA PCS system. A classification means for distinguishing between a public terminal for a public system and a location-based service subscriber terminal using an access overload class; Intermittent synchronous beacon generating means for generating an intermittent synchronous beacon synchronized to any one of a CDMA system time and a broadcasting cycle of a public system; And an automatic switching means for automatically switching only the location-based service subscriber station of the idle state entered into the location-based service system coverage using the intermittent synchronization beacon.

Here, the location-based service subscriber station is set to a value different from the public terminal, the value of the access overload class, the automatic switching means is different from the public terminal, entering the location-based service macrocell Control to switch only the terminal having the value of the access overload class set to the value to the location-based service system.

The intermittent synchronization beacon transmits an overhead message different from the location-based service system through a separate beacon paging channel, so that only the terminal having a value of an access overload class set to a different value from the public terminal is used. Control to switch to location based service system.

The intermittent synchronous beacon also adjusts the digital gain for the beacon sector in the channel in synchronization with the broadcasting cycle of the public system.

In addition, the intermittent sync beacon is transmitted in synchronization at the time when the broadcasting cycle of the public system starts.

The intermittent sync beacon includes only a system parameter message and a global service redirection message (GSRM) in an overhead message included in a paging channel of the intermittent sync beacon, and the system parameter message and the GSRM in one paging channel slot. It is made to include.

The intermittent sync beacons also have coverage equal to or less than the location based service system coverage.

The intermittent synchronization beacon generating means may further include: a channel element for pilot channel for outputting a pilot signal for a beacon sector; A synchronization channel element for outputting a synchronization signal for the beacon sector; A paging channel element for outputting a paging signal allocated to the intermittent synchronization beacons; A digital synthesizer for synthesizing the pilot channel channel element with the outputs of the sync channel element and the paging channel element; And means for distributing the output of the digital synthesizer into various frequency allocation signals and upconverting to an RF frequency band to output intermittent synchronization beacons.

In order to achieve the above object, an automatic roaming method for a location-based service according to the present invention includes a mobile terminal in an automatic roaming method between a location-based service system and a public system having different frequency allocation using a location-based service macrocell. Entering into the location based service macrocell coverage and handing off to a location based service system; Receiving a Global Service Redirection Message (GSRM) from a location based service macrocell; Among the UEs receiving the GSRM, the location-based service subscriber station switches the system to the location-based service system, and the public terminal other than the location-based service subscriber station ignores the GSRM.

In addition, the automatic roaming method for a location-based service according to the present invention in order to achieve the above object, in the automatic roaming method between a location-based service system and a public system having a different frequency allocation using an intermittent synchronization beacon, the mobile terminal is intermittent Entering synchronous beacon coverage to maintain the public system; Detecting, by the location-based service subscriber station in the idle state, the intermittent sync beacon at the time of transmission of the intermittent sync beacon, and handing off the idle to the intermittent sync beacon; Receiving a Global Service Redirection Message (GSRM) from the intermittent synchronization beacon signal by the location-based service subscriber station performing idle handoff with the idle intermittent synchronization beacon; And receiving the GSRM by the location-based service subscriber station, switching the system to a location-based service system according to the GSRM.

1 is a view for explaining a method for implementing automatic roaming between systems having different frequencies by building a location based service (LBS) macrocell,

FIG. 2 is a diagram for describing a method for implementing automatic roaming between systems having different frequencies using an intermittent synchronous beacon; FIG.

3 is an exemplary timing diagram illustrating a transmission time point of an intermittent synchronization beacon;

4 illustrates an embodiment of an intermittent sync beacon.

<Description of the symbols for the main parts of the drawings>

101,101 ': base station in public system

102: base station of LBS macrocell

103: base station of the LBS system

111,111 ': Base station coverage of public system

112: base station coverage of an LBS macrocell

113: base station coverage of the LBS system

202: Intermittent Synchronous Beacon Equipment

212: Coverage of Intermittent Synchronous Beacons

401 ~ 405: Channel element 411,411 ': Digital synthesizer

412: transceiver 412 ': conventional beacon

414 linear amplifier

Hereinafter, an automatic roaming system and method for a location based service system according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 illustrates an embodiment of an automatic roaming method for constructing an LBS macrocell and using the same to control system switching between systems having different frequency allocations (public system: FAv, LBS system: FAω).

In the figure, reference numerals 101 and 101 'denote base stations of a public system, reference numeral 102 denotes a base station of an LBS macrocell, and reference numeral 103 denotes a base station of an LBS system. Reference numerals 111 and 111 'denote base station coverage of the public system, reference numeral 112 denotes base station coverage of the LBS macrocell, and reference numeral 113 denotes base station coverage of the LBS system.

Here, the base station 102 of the LBS macrocell may be a base station for a public system having coverage overlapping with the base station coverage 113 of the LBS system, or may be some sector of the base station for the public system.

When the mobile station enters the base station coverage 112 of the LBS macrocell from the base station coverage 111 and 111 'of the public system, the mobile station performs a handoff to the base station 102 of the LBS macrocell. That is, mobile terminals in idle state perform idle handoff, and busy terminals perform soft / soft handoff (or hard handoff). Subsequently, the mobile terminal in the idle state of the LBS subscriber station existing in the LBS system switches the system to the base station 103 of the LBS system under the control of the base station 102 of the LBS macrocell. However, when the general public terminal and the LBS subscriber station in the call exist in the LBS macrocell area, the system is not switched to the LBS system.

The method of controlling the LBS subscriber stations existing in the LBS macrocell to switch to the LBS system is as follows.

The CDMA standard (IS-95A / B, CDMA2000, etc.) defines 16 "Access Overload Classes" (hereinafter referred to as "AOC") for access overload control. CDMA mobile communication terminals have a 4-bit variable, ACCOLC _p , to store the AOC to which the terminal belongs. The value of ACCOLC _p is automatically set to equally distribute from AOC 0 to AOC 9 according to the IMSI value when the International Mobile Station Identification Number (IMSI) value of the terminal is set. AOC 10 is used for testing, AOC 11 is used for emergency purposes, and AOC 12 to AOC 15 are not used as reserves for future use. The ACCOLC _p value of the terminal may be set to a specific AOC using a separate dedicated tool. In the present invention, ACCOLC _p of LBS subscriber stations is set to AOC 12 to AOC 15 using such a dedicated tool.

Meanwhile, the Global Service Redirection Message (GSRM) of the CDMA standard is an overhead message that is periodically transmitted and is used to instruct terminals of specific AOCs to switch to a specific system. Accordingly, the LBS macrocell base station converts terminals corresponding to AOC 11 to AOC 15 to which the LBS subscriber station belongs to the LBS system using a GSRM message.

This method can control only specific LBS subscriber stations to access a specific LBS system, but in order to configure an LBS macrocell, it is difficult to re-engineer the coverage of an existing public system that is already established. There is this. In particular, when building a small LBS system at the building level or floor level, it is difficult to construct an LBS macrocell itself. Therefore, this method can be used for large sites that can easily redesign public systems such as factory towns, university campuses, and military units. Can be used as a center.

Meanwhile, in this method, when the base station coverage 112 of the LBS macrocell is larger than the base station coverage 113 of the LBS system, the base station coverage 112 of the LBS macrocell is included in the base station coverage 113 of the LBS system. "LBS subscriber station repeatedly repeats the system switching between the LBS macrocell and the LBS system" (hereinafter referred to as the "Ping-Pong phenomenon") that exists in an area that does not belong to may occur. That is, the terminals present in this area receive the GSRM message from the base station of the LBS macrocell, switch to the LBS macrocell, attempt to acquire the system by tuning to the base station of the LBS system, but fail to acquire the LBS system, and again, the system initialization step. After returning to the LBS macrocell, the process is repeated repeatedly. When the ping-pong phenomenon occurs, the terminal is almost impossible to service. Thus, the base station (or sector) coverage 112 of the LBS macrocell should be designed to be smaller or equal to the base station coverage 113 of the LBS system.

On the other hand, when the LBS subscriber stations out of the coverage 113 of the LBS system, the handoff (Idle / Hard) to the public system by using the existing frequency allocation (FA) handoff method.

2 is an exemplary diagram of the present invention, showing an embodiment of automatic roaming between systems with different frequency assignments using intermittent sync beacons.

In FIG. 2, reference numeral 202 denotes intermittent synchronous beacon equipment, and reference numeral 212 denotes coverage of intermittent synchronous beacons. The intermittent sync beacon equipment is installed in the base station 103 of the LBS system, in order to prevent the ping-pong phenomenon, the coverage 212 of the intermittent sync beacon should be smaller than or equal to the coverage 113 of the LBS system.

The intermittent sync beacon signal includes only a pilot channel, a sync channel, and a paging channel. The pilot channel and the sync channel use the same channel elements as the base station signals of the LBS system, while the paging channel uses separate channel elements allocated for intermittent sync beacons. Therefore, the paging channel message of the intermittent sync beacon may be different from the paging channel message of the LBS system base station.

Unlike conventional beacons, intermittent sync beacons are transmitted in synchronization with the CDMA system time (or, more accurately, the broadcasting cycle of the system to be tuned). In addition, the transmission period (period) is longer than the existing beacons and the transmission duration (duration) is very short. For example, an intermittent sync beacon may be sent with a duration of 640 ms at a period of 82.16 seconds.

In case of implementing automatic roaming between systems having different frequency assignments using intermittent synchronous beacons, the LBS subscriber station must also support the function of receiving a broadcasting message.

The operation of the terminal is different between the general public terminal and the LBS subscriber terminal, and also depends on the state of the terminal.

When the LBS subscriber terminal or the public terminal enters the coverage 212 of the intermittent sync beacon in a call state, these terminals do not recognize the intermittent sync beacon. Only a slight degradation in call quality may occur during the transmission duration of the intermittent sync beacons. However, due to the long beacon cycle and very short transmission duration, the degradation of the call quality is negligible.

On the other hand, the LBS subscriber station operates in the same manner as when entering the coverage 212 of the intermittent sync beacon in the idle state when the call is terminated in the coverage 212 of the intermittent sync beacon.

When the LBS subscriber station enters the coverage 212 of the intermittent sync beacon in the idle state, when the intermittent sync beacon is detected, the IBS handoff is performed by the intermittent sync beacon. Thereafter, GSRM is received through the intermittent sync beacon's paging channel and the system is switched to the LBS system.

When the public terminal other than the LBS subscriber terminal enters the coverage 212 of the intermittent sync beacon in the idle state, when the intermittent sync beacon is detected, the idle handoff is performed as the intermittent sync beacon. However, even if the GSRM is received through the paging channel of the intermittent synchronous beacon, the AOC is different so that the system does not switch to the LBS system. Then, when the intermittent sync beacon signal disappears, Idle handoff is performed again with the original public system.

On the other hand, when the LBS subscriber stations out of the coverage 113 of the LBS system, the handoff (Idle / Hard) to the public system by using the existing frequency allocation (FA) handoff method.

3 is an embodiment showing the transmission timing of the intermittent synchronization beacons according to the present invention.

Reference numeral 301 denotes a broadcast cycle when the BCI (Broadcasting Cycle Index) is 6 in the public system. In this case, the broadcast cycle has a period of 82.16 seconds (1027 paging slot). Reference numeral 304 denotes an intermittent sync beacon cycle when the cycle of the intermittent sync beacon consists of two broadcast cycles. In this case, the intermittent synchronous beacon cycle has a period of 163.32 seconds (2054 paging slot).

Reference numerals 302 and 303 denote the timing of transmission of these beacon signals assuming that intermittent sync beacons are transmitted using FA v and FA v '. The timing of transmission of intermittent sync beacons coincides with the beginning of the broadcast cycle. If the intermittent sync beacons are transmitted to multiple FAs and the period of the intermittent sync beacons consists of several broadcast cycles, the transmission times for each frequency allocation (FA) of each intermittent sync beacons are uniformly distributed among all LBS subscriber stations. You can do that. Intermittent synchronization beacons (FA υ 302) and the intermittent synchronization beacons (FA υ ', 303) transmission time is an example that occurs alternately in broadcast cycle units.

Reference numeral 305 denotes a transmission duration of the intermittent sync beacons. The transmission duration of the intermittent synchronous beacon may be set in an integer multiple of a paging channel slot (80 ms), in which terminals determine an idle handoff from the public system and an idle hand as an intermittent synchronous beacon. It is set to a length enough to receive GSRM from the paging channel of the intermittent synchronous beacon (approximately 480ms to 1280ms) by performing the off. However, it should be set to a value as small as possible to minimize the degradation of the call quality of the mobile terminal through the public system around the intermittent synchronous beacon coverage and the success rate of the incoming call through the public system around the intermittent synchronous beacon coverage.

Figure 4 (a) is a block diagram showing an example of implementing the intermittent synchronization beacon according to the present invention using the LBS system and the existing beacon device.

Intermittent sync beacons operate in synchronization with CDMA system time. In order to satisfy this characteristic, the beacon device receives the CDMA system time and adjusts the analog gain for each beacon's frequency allocation (FA), or as in the example shown in FIG. Intermittent synchronous beacons can be implemented by using the device and by adjusting the digital gain of the beacon signal at the channel end of the LBS system.

Reference numerals 401 to 404 denote channel elements for pilot channels, channel elements for sync channels, channel elements for paging channels, and communication channels in the base station of the LBS system, respectively. For channel elements. Reference numeral 405 denotes a channel element for a paging channel allocated for an intermittent synchronization beacon in a base station of an LBS system.

The base station signal of the LBS system includes the outputs 406-409 of the base station sectors for the LBS system of the channel elements 401 to 404 synthesized by the digital synthesizer 411, and the RF frequency bands FAυ, υ ', After up-converting to ..., it is amplified by the linear amplifier 414 and then transmitted through the antenna.

On the other hand, for the intermittent synchronous beacon signal, the beacon sector output 406 'of the pilot channel channel element 401, the beacon sector output 407' of the synchronization channel element 402, and the paging allocated to the intermittent synchronous beacon The output 410 of the channel 405 is synthesized in the digital synthesizer 411 'and distributed to multiple frequency allocation (FA) signals in the existing beacon equipment 413 and into the RF frequency bands (FAω, ω', ...). After up-converting, the signal is amplified by the linear amplifier 414 and then transmitted through an antenna.

In order to synchronize the transmission timing of the intermittent synchronous beacons with the broadcasting period of the public system, the beacon sector output 406 'of the pilot channel channel element 401 and the beacon sector output of the synchronization channel element 402. 407 ', and the output 410 of the paging channel 405 assigned to the intermittent sync beacon, adjusts the digital gain according to the period and transmission duration of the intermittent sync beacon as shown in FIG.

On the other hand, the present invention is not limited to the above-described typical preferred embodiments, but can be carried out in various ways without departing from the gist of the present invention, various modifications, alterations, substitutions or additions are common in the art Those who have knowledge will easily understand. If the implementation by such improvement, change, replacement or addition falls within the scope of the appended claims, the technical idea should also be regarded as belonging to the present invention.

According to the method and apparatus for automatic roaming between the LBS system and the public system in which the frequency allocation (FA) of the present invention configured as described above can be controlled so that only LBS subscriber stations can be converted to the LBS system, LBS local to LBS subscribers. Specialized services can be made available at low cost.

The LBS macrocell can be applied to large sites such as factory towns, campuses, and amusement parks. The intermittent synchronous beacon can be applied to relatively small sites such as government offices, department stores, single buildings, and single floors. can do.

Since the public terminals do not detect the existence of the LBS system and use only the public system, the method proposed in the present invention has little effect on the existing public system and the public terminal.

Moreover, when using the method proposed in the present invention, there is an advantage that can be utilized as LBS subscriber terminal without replacing most existing general terminals. That is, a general terminal supporting a broadcasting message reception function can be utilized as an LBS subscriber terminal without replacing the terminal, thereby reducing the cost burden due to the terminal replacement.

Claims (15)

In a location based service system having different frequency allocations and a public system of a CDMA cellular and / or CDMA PCS system, Classification means for distinguishing between a public terminal for a public system and a location-based service subscriber terminal using an access overload class; Location comprising the automatic switching means for configuring the location-based service macrocell to automatically switch only the location-based service subscriber station of the idle state entered into the location-based service system coverage to the location-based service system Automatic roaming system for infrastructure service systems. The method of claim 1, The location-based service subscriber station is set to a value different from the public terminal of the value of the access overload class, The switching means controls to switch only a terminal having a value of an access overload class set to a value different from the public terminal entering the location-based service macrocell to the location-based service system. Roaming system The method of claim 1, The location-based service macrocell is an automatic roaming system for a location-based service system, characterized in that having a coverage equal to or less than the location-based service system coverage. The method of claim 2, The automatic switching means uses a periodically transmitted overhead message to enter a terminal having a value of an access overload class set to a different value from the public terminal, which has entered the location-based service macrocell coverage. Automatic roaming system for a location-based service system, characterized in that the automatic switching. The method of claim 4, wherein The overhead message includes an automatic roaming system for a location-based service system, characterized in that it comprises a Global Service Redirection Message (GSRM) for the location-based service subscriber station. In a location based service system having different frequency allocations and a public system of a CDMA cellular and / or CDMA PCS system, Classification means for distinguishing between a public terminal for a public system and a location-based service subscriber terminal using an access overload class; Intermittent synchronous beacon generating means for generating an intermittent synchronous beacon synchronized to any one of a CDMA system time and a broadcasting cycle of a public system; A location-based service system comprising an automatic switching means for automatically switching only the location-based service subscriber station of the idle state entered into the location-based service system coverage using the intermittent synchronization beacons; Automatic roaming system. The method of claim 6, The location-based service subscriber station is set to a value different from the public terminal of the value of the access overload class, The automatic switching means controls to switch only a terminal having a value of an access overload class set to a value different from the public terminal entering the location-based service macrocell to the location-based service system. Automatic roaming system for your system. The method of claim 6, The intermittent synchronous beacon transmits an overhead message separate from the location-based service system through a separate beacon paging channel, thereby location-based only the terminal having a value of an access overload class set to a different value from the public terminal. An automatic roaming system for a location based service system, characterized by controlling to switch to a service system. The method of claim 8, And the intermittent sync beacon adjusts the digital gain for the sector for the beacon in the channel in synchronization with the broadcast period of the public system. The method of claim 6, The intermittent synchronization beacons are automatically roaming system for a location-based service system, characterized in that the transmission is synchronized when the broadcast period of the public system starts. The method of claim 6, The intermittent sync beacon includes only a system parameter message and a global service redirection message (GSRM) in an overhead message included in a paging channel of the intermittent sync beacon, and includes the system parameter message and the GSRM in one paging channel slot. Automatic roaming system for a location-based service system, characterized in that. The method of claim 6, And the intermittent sync beacon has a coverage equal to or less than the location based service system coverage. The method of claim 6, The intermittent synchronous beacon generating means, A pilot channel channel element for outputting a pilot signal for the beacon sector; A synchronization channel element for outputting a synchronization signal for the beacon sector; A paging channel element for outputting a paging signal allocated to the intermittent synchronization beacons; A digital synthesizer for synthesizing the pilot channel channel element with the outputs of the sync channel element and the paging channel element; And means for distributing the output of the digital synthesizer into multiple frequency allocation signals and upconverting to an RF frequency band to output intermittent synchronization beacons. In an automatic roaming method between a location-based service system and a public system having different frequency assignment using a location-based service macrocell, The mobile terminal entering the location based service macrocell coverage and handing off to the location based service system; Receiving a Global Service Redirection Message (GSRM) from a location based service macrocell; The location-based service system comprising the step of switching the system to a location-based service system of the terminal receiving the GSRM and the public terminal other than the location-based service subscriber station ignores the GSRM Roaming method for An automatic roaming method between a location based service system and a public system having different frequency allocation using intermittent sync beacons, The mobile terminal entering intermittent synchronous beacon coverage to maintain the public system as it is; Detecting, by the location-based service subscriber station in the idle state, the intermittent sync beacon at the time of transmission of the intermittent sync beacon, and handing off the idle to the intermittent sync beacon; Receiving a Global Service Redirection Message (GSRM) from the intermittent synchronization beacon signal by the location-based service subscriber station performing idle handoff with the idle intermittent synchronization beacon; And a location-based service subscriber station receiving the GSRM, switching the system to a location-based service system according to the GSRM.